Seems a little suss to me, as I have been a loyal user of Safari since its first release - and have built many pages using @import - and it hasn't skipped a beat.

Is this possible? I know early versions of Safari had some odd rendering problems, but crashing because of a simple piece of code seems a bit hard to believe.

Not sure which version of OS X they are using, but if they are using the first release of Safari on one of the early OS X, could this perhaps be causing these issues?

If someone can give me a definate "no", and a quick reason why it would be great

Not sure if this is any help at all...but I was using Safari 1.2 and it was frequently crashing on certain sites (ebay for example). I had no idea how to fix it so I updated my old version of pith-helmet (The safari filer) to the newer version and I have had no problems sense.